1. Field of the Invention
The embodiments of the invention generally relate to semiconductor structure interconnects and more particularly to a spring interconnect structure that provides stress relief.
2. Summary
Semiconductor die (integrated circuits) are having increasing levels of complexity, performance, reliability and thermal demand being placed upon them. All technology roadmaps point to size factors as being required to decrease. There is much activity in the area of die interconnect to the package. High density interconnects typically use Controlled Chip Collapse Connection (C4) technology (though it is not required for this invention). The industry is moving to smaller C4 ball size and Lead-free materials, both of which result in higher stresses being placed directly upon the interconnect. Thermal and reliability demands also put these interconnects into modes which work against the high reliability requirements also being placed upon the interconnect.
Currently, the industry is attempting to manage the stresses at this interface a number of ways: 1) limiting thermal levels; 2) limiting thermal cycles; and 3) manipulating the Lead-free materials to reduce the stresses (though they typically increase costs), to name a few. Managing the stresses using the methods above, while effective, may not be the most effective way of dealing with the stresses. Therefore, the present disclosure utilizes a ‘MEMs-switch-like’ structure to allow for a controlled expansion at the joint, thus reducing the stresses at the fail location, and maintaining a low cost manufacturing process with higher reliability. “MEMs” refers to micro-electromechanical structures.
More specifically, the embodiments herein provide a semiconductor interconnection that comprises a semiconductor device, a substrate adjacent the semiconductor device, and a plurality of spring contacts on the semiconductor device or the substrate. A plurality of solder connections are on the opposite semiconductor device or substrate. Each spring contact comprises a contact surface and a conductive material on the contact surface. More specifically, each of the spring contacts comprises a beam and either: an empty gap below the beam; or a compressible material below the beam. Upon assembly of the semiconductor device and the substrate, the conductive material on the plurality of spring contacts makes contact with each of the plurality of solder connections. The conductive material is in a liquid state at manufacturing or operating temperatures of the semiconductor device. Thus, the conductive material could be a solid at room temperature and transition to a liquid state at the semiconductor's manufacturing or operating temperatures.
These and other aspects of the embodiments of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments of the invention and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments of the invention without departing from the spirit thereof, and the embodiments of the invention include all such modifications.